Exam #1 in class (bring cheat sheet) Take-home portion due at start of in class exam. dukkha.html Skills needed for the exams: dukkha.html 1. Understand material from lecture. Quizzes can help diagnose. Be self-critical and skeptical. Skills needed for the exams: 1. Understand material from lecture. 2. Be able to apply the information.Skills needed for the exams: dukkha.html 2. Be able to apply the information. Lecture is presented linearly, but applying the information may mean seeing it non- linearly. Skills needed for the exams: dukkha.html 3. Communicate what you know. If I answered your question with what you wrote down, would it make sense? Skills needed for the exams: 1. Understand material from lecture. 2. Be able to apply the information. 3. Communicate what you know. Skills needed for the exams:dukkha.html What makes us who we are? Nature and Nurture Based on Nature via Nurture by Matt Ridley (2003) 23 pairs of human chromosomes of each pair is from mom and the other from dad. Protein Genes code for proteins. Cells function because of proteins. Organisms are collections of cells. CB 5.26 Protein The connection between genes and traits is rarely direct. What influences traits? Nature or Nurture? CB 5.26 Nurture Imprinting: exposure to movement (environment) sets mother Nature X/Y chromosomes in humans: genes = traits XY XX Twin studies have been used to determine the heritability of various traits. Types of twins: Twin studies have been used to determine the heritability of various traits, but there are some caveats: How many twins have been studied? How different are the environments? Correlation of weight (BMI)% Identical twins reared together80 Identical twins reared apart72 Fraternal twins reared together43 Biological siblings34 Parents and children living together26 Adopted children and parents 4 Unrelated children living together 1 *But food preference shows little genetic correlation Correlation of weight and relatedness The nature of environmental influences on weight and obesity: A behavior genetic analysis. Grilo, Carlos M.; Pogue-Geile, Michael F.; Psychological Bulletin, Vol 110(3), Nov pp And two books by Matt Ridley: Nature via Nurture (2003) and Genome: the Autobiography of a Species in 23 Chapters (1999) Intelligence Correlation of IQ Inheritance :% The same person tested twice87 Identical twins reared together86 Identical twins reared apart76 Fraternal twins reared together55 Biological siblings47 Parents and children living together40 Parents and children living apart31 Adopted children living together 0 Unrelated people living apart 0 From two books by Matt Ridley: Nature via Nurture (2003) and Genome: the Autobiography of a Species in 23 Chapters (1999) Proof or disproof? Correlation of IQ Inheritance :% The same person tested twice87 Identical twins reared together86 Identical twins reared apart76 Fraternal twins reared together55 Biological siblings47 Parents and children living together40 Parents and children living apart31 Adopted children living together 0 Unrelated people living apart 0 From two books by Matt Ridley: Nature via Nurture (2003) and Genome: the Autobiography of a Species in 23 Chapters (1999) When the environment is equal (everyone has access to resources), genetic differences are magnified. When environments are different (only a few have access to resources), environmental differences are magnified. Children of alcoholic parents are likely to become alcoholics Nature or Nurture? What determines human sexuality? Twin Studies: Chance of homosexual male having homosexual brother: Bailey and Pillard (1991) 52% (29/56) of identical twins 22% (12/54) of fraternal twins 11% (6/57) of adoptive brothers Correlation of homosexual brothers but not homosexual brother and sister Correlation of homosexual sisters but not homosexual sister and brother There is no gay gene. There are thousands of genes and billions of interconnected neurons. There are likely many genes affecting sexuality. Environmental effects may also play a role in determining sexuality. Birth order: Each elder brother increases probability of homosexuality by 1/3. Environmental effects on homosexuality Birth order: Each elder brother increases probability of homosexuality by 1/3. Birth weight: Boys born as younger sons have lower birth weight. Fig 2. BIRTH WEIGHT, SEXUAL ORIENTATION AND THE SEX OF PRECEDING SIBLINGS (2001) RAY BLANCHARD AND LEE ELLIS J. biosoc. Sci. 33, 451467 Birth Weight, Sexual Orientation and the Sex of Preceding Siblings Fig 2. BIRTH WEIGHT, SEXUAL ORIENTATION AND THE SEX OF PRECEDING SIBLINGS (2001) RAY BLANCHARD AND LEE ELLIS J. biosoc. Sci. 33, 451467 Homosexual males with older brothers have a lower birth weight. Environmental effects on homosexuality Birth order: Each elder brother increases probability of homosexuality by 1/3. Birth weight: Boys born as younger sons have lower birth weight. Mothers may have immune reaction against male proteins. NATURE VOL 404 pg 455 (30 MARCH 2000) Finger length can be related to fetal androgen exposure Index to ring finger ratio NATURE VOL 404 pg 455 (30 MARCH 2000) Finger Length and Homosexuality N= Sexuality: Genetic? Twin studies... Environmental? Birth order: Each elder brother increases probability by 1/3. Is one more or less inevitable? Both nature and nurture determine human sexuality. Is one more of a choice? MWF class, lecture ended here. These last few slides may help you better understand nature and nurture. TTh class lecture ended 5 slides further. Vision: optic nerves must connect to brain Absence of light during early development causes permanent inabilities to interpret visual signals. Searched for gene using blind mice Genes such as BDNF and GAD65 are turned on by visual stimulus. Without the expression of these genes, neurons do not properly connect. Environment changes gene expression; gene expression changes perception of environment. Exam #1 in class (bring cheat sheet) Take-home portion due at start of in class exam.